A charged particle (charge q ) is moving in a circle of radius R with uniform speed v. The associated magnetic moment μ is given by :
qvR/2
qvR2
qvR
A coil of one turn is made of a wire of certain length and then from the same length a coil of two turns is made. If the same current is passed is both the cases, then the ratio of the magnetic induction at their centers will be
2 : 1
1 : 4
4 : 1
1 : 2
The magnetic induction at a point P which is at the distance of 4 cm from a long current carrying wire is 10-3 T. The field of induction at a distance 12 cm from the current will be
3.33 × 10-4 T
1.11 × 10-4 T
3 × 10-3 T
9 × 10-3 T
A 10 eV electron is circulating in a plane at right angles to a uniform field of magnetic induction 10-4 Wb/m2 ( =1.0 gauss). The orbital radius of the electron is
12 cm
16 cm
11 cm
18 cm
Magnetic field due to 0.1 A current flowing through a circular coil of radius 0.1m and 1000 turns at the centre of the coil is
0.2 T
2 × 10-4 T
6.28 × 10-4 T
9.8 × 10-4 T
Tesla is the unit of
magnetic flux
magnetic field
magnetic induction
magnetic moment
Current is flowing in a coil of area A and number of turns N, then magnetic moment of the coil, M is equal to
NiA
Ni/A
N2Ai
A straight wire of length 0.5 m and carrying a current of 1.2 A is placed in uniform magnetic field of induction 2 T. The magnetic field is perpendicular to the length of the wire. The force on the wire is
2. 4 N
1.2 N
3.0 N
2.0 N
A uniform magnetic field acts right angles to the direction of motion of electrons. As a result, the electron moves in a circular path of radius 2 cm. If the speed of electrons is doubled, then the radius of the circular path will be
2.0 cm
0.5 cm
4.0 cm
1.0 cm
A beam of electrons is moving with constant velocity in a region having simultaneous perpendicular electric and magnetic fields of strength 20 Vm-1 and 0.5T, respectively at right angles to the direction of motion. Then the velocity of electrons must be :
8 m/s
20 m/s
40 m/s
1/40 ms
